为什么 lambda 指令返回不同的结果？

Question

import pandas as pd

df = pd.DataFrame([['AB,CD'],['AB,FJS'],['DG']],
                   index = [1,2,3],columns=['A'])

Why do the following two codes return different results

for i in df["A"]:
    for n in i.split(","):
        print(n)

which returns

AB
CD
AB
FJS
DG

but the other code

def fx(x):
    for i in x["A"]:
        for n in i.split("，"):
            print(n)
df.apply(lambda x: fx(x), axis = 1)

returns

A
B
,
C
D
A
B
,
F
J
S
D
G

So, why does lambda return different results? And how can I change the lambda code to return the same results as the previous one? Thanks in previous

Answer 1

The results are different because lambda function is applied to each row separately. So, for example, in the first row x is AB,CD and when you write for i in x["A"] , you iterate over each separate symbol.

def fx(x):
    for i in x["A"].split(","):
        print(i)
df.apply(lambda x: fx(x), axis = 1)